Rheostat



No. 770,472. PATENTED SEPT. 20, 1904.

J. NELSON.

RHEOSTAT.

APPLICATION FILED JULY 5 1904. NO MODEL. 3 SHEETS-SHEET 1- No. 770,472.PATENTED SEPT. 20, 1904. J. NELSON.

RHEOSTAT.

APPLIOATION FILED JULY 5, 1904. N0 MODEL. 3 SHEETS-SHEET 2 172%??? 217272 jzyorz,

PATENTED SEPT. 20, 1904.

J. NELSON.

RHEOSTAT.

APPLIOATION FILED JULY 5. 1904.

3 SHEETS-"SHEET 3.

N0 MODEL.

Patented September 20, 1904,

JOHN NELSON, OF PERU, ILLINOIS.

semester.

SPECIFICATION forming part of Letters Patent No. 770/272, datedSeptember 20, 1904. Application filed July 5, 1904:. Serial No. 215,385.(No model.)

To aZZ whom, it may concern.-

Be it known that I, JOHN NnLsoN, a citizen of the United States,residing at Peru, in the county of Lasalle and State of Illinois, haveinvented a new and useful Improvement in Rheostats, of which thefollowing is a specification.

My invention relates particularly to rheostats which may be employed forproducing a wide variation in the resistance of an electric circuit; andmy primary object is to provide a rheostat of this character of simpleand compact construction which is capable of introducing into a circuitresistance which may be readily varied from zero to the highestresistance usually desirable in this class of instruments.

My invention is illustrated in the accompanying drawings, in whichFigure 1 represents a plan view of a rheostat embodying my improvements;Fig. 2, a side elevational view of the same viewed as indicated at line2 of Fig. 6; Fig. 3, a longitudinal section taken as indicated at line 3of Fig. 6; Fig. 4, a longitudinal section taken as indicated at line aof Fig. 6; Fig. 5, an end elevational view; Fig. 6, a transverse sectiontaken as indicated at line 6 of Fig. 3; and Fig. 7, a broken transversesection, partly diagrammatic in its nature, illustrating the manner inwhich the resistance-coils are supported.

In the preferredconstruction, A represents a frame which may beconveniently attached to a wall within easy reach from the floor; B B,two series of standards having insulated connections, respectively, withthe two longitudinal or vertical frame members; B

B two series of contactbloclts arranged in parallel longitudinal columnsand having insulated connections at one side of the longitudinal centerof'the frame and having insulated connections with the longitudinalframe member 13*; O O, two series of resistance coils arranged inparallel columns at opposite sides of the contact-blocks B B; D, a slideconnected with the contact-blocks; ID, a longitudinally-extendingconductor or bar forming a portion of a short-circuiting device andarranged beneath the slide D and having insulated connection with theframe member IS";

F, a switch-lever pivotally connected with one end of the bar E; G, aconductor in circuit with a battery (5? and connected with thecorresponding end members of the standards B B; S M, contact-blocksconnected, respectively, with the corresponding end members of thecontact-blocl s B B", and W a contactbloel; located adjacent to theblock M and having insulated connection with the adjacent member 1%.

Commencing with the near or lower end of the device, the iirst one ofthe standards B is joined by a rod 7/ to the first one of the blocks B,the second one of the standards I3 is joined by a rod 6 to the third oneof the blocks E the third one of the standards B is joined by a rod V tothe fifth one of the blocks B and the fourth one of the standards Bisjoined by a rod 6 to the seventh one of the blocks Sin'nlarly thestandards B are joined by a series of rods 0 to c, inclusive, toalternate ones of the blocks P The first resistance-coil O is connectedat its outer end with the upper portion of the standard l3 and at itsinner end with the lower por tion of the block B. The second coil O isconnected at its outer end with the lower portion of the standard 13 andat its inner end with the upper portion of the block B The same methodfollowed throughout in connecting the remaining coils of the C serieswith their appropriate standards and contactblocks. The coils aregrouped in pairs, so that two coils lie between each two pairs of rods.In a similar manner the coils of the C series are grouped and connectedwith their respective standards and contact-blocks. Thus the first coilC is connected at its outer end with the upper portion of the standard Band at its inner end with the lower portion of the contact-block B", thesecond coil is connected at its outer end with the lower portion of thesecond standard B and at its inner end with the upper portion of thesecond contact-block B, and so on.

The uppermost pair of contact-blocks are entirely insulated and mayserve to receive the slide when all of the coils are in use. The twocolumns of con tactblocks B L are spaced to receive the slide I) andhave inturn ed lianges,

as shown in Fig. 6. The slide comprises an upper member (Z; alowermember (1; depending bolts (5 secured to the upper member (Z and passingloosely through the member (Z; springs (Z confined on the lower ends ofsaid bolts and serving to yieldingly force the members (Z (Z together toinsure intimate contact with the flanges of the blocks B B, and ayielding shoe CZ, depending from the member cl and bearing on the bar EThe member (Z is equipped with a handle d.

Assuming the switch-lever F to be in the position shown in Fig. 5, it isevident that the bar E performs no function. Assuming the switch-leverto be upon the block M, which is electrically connected with the firstone of the series of blocks B it is evident that the coils of the Cseries will be short-circuited and the current will pass through the rod0, the first one of the blocks 13 the block M, the switchlever F, thebar E, shoe (5, slide 1), rod Z), and thence back through the cut-incoils of the C series to the battery. Assuming the lever F to be on thecontact-block S, the coils of the C series will be short-circuited,while the coils of the C series will be in use. In this explanation itis to be understood that the slide D has been assumed to be in theposition shown in Fig. 1 and that the coils concerned are the coilsbelow the slide. Obviously the slide may be raised or lowered to cut inor cut out resistance.

From the foregoing explanation it will be understood that with the slideD in a given position a weak, medium, or strong current may be obtained,according to the position of the switch-lever F, and it will be noticedthat the reference-letters of the blocks TV, M, and S correspond withthe initials of the words lVeak, Medium, and Strong. In practice theblocks are so marked on the apparatus. As probably has been inferred,the coils C are of greater length than the coils O, and hence of greaterresistance. The grouping of the coils and the arrangement of the rods isan advantageous one, as will be readily understood.

A rheostat of the construction set forth is of particular value inconnection with currents of low voltage such as are employed, forinstance, in electroplating. The standards and contact-blocks are ofsuitable size and shape to enable the connections to be made in themanner stated; but obviously the device may be altered in theseparticulars without departure from my invention.

It readily will be understood that the mechanical construction may bevaried greatly Without departure from my invention. Hence I wish to beunderstood as intending no undue limitation from the foregoing detaileddescription.

\Vhat I regard as new, and desire to secure by Letters Patent, is

l. The combination of a series of coils of a given resistance connectedwith a series of contact members, a second series of coils of lessresistance connected with a second series of contact members, a slideconnected with said contact members, connections joining the free endsof appropriate coils of each series, and means for short-circuitingeither series of coils, for the purpose set forth.

2. The combination of two series of resistance-coils and two series ofcontact members connected therewith, a slide adapted to move on saidcontact members, suitable connections at the free ends of the coils, aconductor, and a contact-piece connected with said slide and engagingsaid conductor, for the purpose set forth.

3. The combination of two series of resistance-coils and two series ofcontact members connected therewith, a slide adapted to move on saidcontact members, suitable connections at the free ends of the coils, aconductor extending parallel with the traverse of the slide, acontact-piece carried by the slide and contacting with said conductor,and a switch for connecting said conductor with the electric circuit,substantially as and for the purpose set forth.

4:. The combination of two series of resistance-coils and two series ofcontact members connected therewith, a slide adapted to move on saidcontact members, suitable connections at the free ends of the coils, aconductor back of the path of said slide, a contact-piece connected withsaid slide and engaging said conductor, and a switch connected with saidconductor and adapted to be connected with an end member of eitherseries of contact members, substantially as and for the purpose setforth.

5. The combination of a frame, two series of parallel standardssupported at the lateral margins thereof, two series of contact-blocksarranged in rows parallel with said standards and intermediate the same,two series of coils arranged in parallel rows on opposite sides of saidcontact-blocks, the coils of each series being connected with theirrespective standards and contact-blocks to cause the current to traversethe coils, and a slide connected with said contact-blocks, substantiallyas and for the purpose set forth.

6. The combination of a rectangular frame, insulated standards supportedalong on lateral margins of the frame, insulated contact-blocks arrangedin two columns parallel with the sides of the frame, two series of coilssupported on the contact-blocks and standards, and a slide connectedwith the contactblocks, substantially as and for the purpose set forth.

7. The combination with a suitable frame of two series of standardsarranged along opposite sides of the frame, two parallel columns ofcontact-blocks arranged between the series of standards, a conductorconnecting one end standard of one series with the adjacent con- IIOtact-block, a conductor connecting the corresponding end standard of theother series with the adjacent contact-block, coils connected with saidlast-mentioned two standards and with the next adjacent contactblocks,coils connected with said last-named contact-blocks and with the nextadjacent standards, additional coils connected with the standards andwith the remaining contact-blocKs in proper sequence, and a slidemovable on said contactbloclis, substantially as and for the purpose setforth.

8. The combination of two series of standards, two series ofcontact-blocks, two series of resistance-coils, two series ofconductors, the coils of each series being arranged in pairs andconnected with appropriate contact-blocks and standards, and thestandards being connected by said conductors to the contact-blocks whichare left unconnected with the coils, and a slide movable on said contactmembers, substantially as and for the purpose set forth.

9. The combination of a suitable frame, two series of standards, twoseries of contactblocks, aslide, a conductor located beneath the path ofsaid slide, two series of resistance-coils, an insulated contact member,and a switch serving to connect said conductor with one of the endblocks of either series or with the said insulated contact member, atwill, substantially as and for the purpose set forth.

JOHN NELSON.

